HF The History of Photography 600pág

64 The invention of photography
Pl 22
existing photographic cameras. Some of these are of particular interest on account of
certain features which were to become essential in camera design.
One camera, claimed to be the oldest, consists of two boxes (like the later Daguerre
cameras) 30 cm. square when closed, the box with the plate-holder sliding within
that holding the lens. This camera has no built-in diaphragm. In another camera of
the same size, the lens-panel and the ground-glass are connected by a locally-made
accordion-like square bellows-the prototype of all bellows cameras to this day. One
slightly larger camera, 31·5 cm. x 35·5 cm. x 40·5 cm., is fitted with a variable metalleaf
iris diaphragm16 to sharpen the image. The bellows and iris diaphragm are novel
features which Daguerre's camera lacked, and were very much ahead of their time.
In order to observe the progress of the image from time to time during the very
long exposure, Niepce had some of the camera boxes pierced with spy-holes which
could be plugged up. The same device was also incorporated in Fox Talbot's cameras
from 1839 onward, but he may have heard of it from Chevalier, who supplied him
with cameras at that period.
It would be tedious to give a description of all the equipment at the Musee Denon,
but we should still single out the first metal camera. It is made of zinc, is 65 cm.
long x 36 cm. high x 36 cm. wide, and bears an old label, 'Chambre noire envoyee
par Daguerre a J. N. Niepce'. This, however, is not the periscope camera obscura
supplied by Daguerre under the partnership agreement. The camera consists of a
single box ; the back with the plate-holder is fixed, but the distance of the lens-panel,
which lies behind the diaphragm, could be varied by means of a handle attached to
the board outside. This camera is also fitted with an iris diaphragm which can be
altered by means of a lever. If the label, which was probably affixed to the camera by
its donor, the Marquis d'Ivry, is correct, Niepce must have added the diaphragm, for
Daguerre obtained his cameras from Chevalier, and the latter stated at a meeting of
the Societe Frarn;:aise de Photographie on 28 May 1858 that he first employed an iris
diaphragm in 1840. We mention this only because the camera as labelled might create
the impression that Daguerre gave Niepce the idea of the diaphragm, whereas the
reverse is the case.